Tubular lamp and holder therefor



Jan. l5, 1946. G. s. MERRILL TUBULAR LAMP AND HOLDER THEREFOR Filed Nov. 25,v 1944 BALLAST Inventor:

G eovge S. Mer`r` I I,

Maw 1 His Attorh ey.

Patented 15, 1946 @ENCE assenso l 'ranma mm mvp norman asignaron George S. Merrill, Cleveland, Ghia, assigner to General Electric Company, a corporation ot New .York

amputation November 25. i944. serial No. como@ 4 claims. los. nrc-sz) This invention relates to tubular lamps such as nuorescent lamps and to lamp holders for such lamps and has for its object to provide a tubular lamp having an improved contact terminal structure and arrangement at its ends and an improved lamp holder for use therewith.v

For a consideration oi' what I believe to be novel and my invention, attention is directed to the following specication and to the claims appended thereto.

In the drawing, Fig. 1 is a side elevation of a tubular lamp and lamp holders embodying the invention; Fig. 2 is a sectional view oi the construction shown in Fig. 1, a wiring diagram being shown diagrammatically in connection with the gure, and Fig. 3 is a view similar to Fig. 2

` with the lamp removed from the holders.

Referring to the drawing, I indicates a tubular lamp and 2 and 3 indicate spaced holders between which the lamp is positioned, the holders being mounted on a, suitable support Il.

According to one feature of my invention, I provide what I term an unbased tubular lamp. That is to say, I do not utilize in myimproved lamp structure terminal bases which are attached to the lamp ends but instead I provide the lamp ends with re-entrant walls li which dene recesses 8 at the inner ends or bottoms of which are located lamp terminal contacts I electrically connected to the cathodes 8 inside the glass envelope of the lamp. The re'-entrant Walls E are formed integral with the side walls oi the lamp and from the same material, such as glass. Preferably, the lamp ends are provided with centrally located conical projections 9 integral with the material of the lamp ends, the terminals I being in the form of washers through which the projections t extend.

By this arrangement, I provide a tubular lamp which is simple in structure and capable of being manufactured at low cost; also, one in which the terminals l, being at the bottom of the recesses are well protected. This latter is especially advantageous since by locating the contacts well within the ends of the lamp I lessen or virtually eliminate the hazard of a person getting an objectional electrical shock on inserting or removing a lamp in case, for example, something had gone wrong with the wiring.

The lamp holder 2 comprises a base having walls which dene a tubular housing Ill having an open end II provided with an inturned iiange I2. Flange I2 forms a stop for a cover disk It of insulating material which is biased against flange 55- I2 by a spring It. In housing I0 is a coiled spring I t which `forms a terminal contact. Its outer end is positioned in an opening I8 in disk I3. Its inner end is fastened by an extension I 'I to a rivet it iixed in the bottom wall of housing I0 and provided with a binding screw I9 for connecting an electrical conductor to the terminal. Also, connectecl to the bottom wall of housing I@ is a. rivet l 2@ which is positioned under the inner end of spring-contact It and is provided with a binding screw 2l for connecting an electrical conductor to the rivet Eil. Rivet 2b forms a terminal contact adapted to be engaged by contact spring I5 when a lamp end is positioned in holder 2.

Lamp holder t is similar in construction to lamp holder 2 except that the tubular housing formed by its walls is oi greater length than the housing i@ and a circuit terminal, corresponding to the circuit terminal 2li of lamp holder 2, is omitted. The lamp holder 3 has wallsvwhich define an axially extending housing 22 having an open end 23 provided with an inturned ange 2li which forms a stop against which a disk 25, ycorresponding to disk I3 of lamp holder 2, is biased by a spring 2t. Attached to the bottom wall oi' housing 22 by a rivet 2l is a contact spring 28, the outer end oiwhich is positioned in an opening 29 at the center oi disk 25. Y In Fig. 2, the wiring for the lamp is illustrated diagrammatically.- The ballast for the lamp,

which in the present instance is indicated as me ing of a known type which comprises an autotransi'ormer, is indicated at 30. The power lines 3l, 82 are connected to the primary of the autotransformer through terminal screws I9, 2l. The secondary of the autotransformer is connected to the terminal screws I9, 2l. When a lamp is not in the lamp holders, the parts of the lamp holders occupy the positions shown in Fig. 3. the terminal spring I5 being out of engagement with contact 2U whereby the primary circuit of the transformer is open. To position a lamp in the lamp holders, the one end of the lamp is rst positioned against disk 25 of lamp holder 3 after which the lamp is moved axially a distance such that its other end clears the lamp holder 2. The

other end o! the lamp is then positioned in the lamp holder 2, as shown in Fig. 2, the lamp being centered by the springs I4 and 28. When the lamp end is positioned in lamp holder 2, spring contact I5 is brought into engagement with terminal contact 20 thus closing the primary circuit oi' the transformer. To remove a lamp from the lamp holders, it must be first moved to the right until its left hand end clears holder 2 after which it may be brought downat an angle and removed from holder 3. It will be seen that as soon is the lamp is moved toward the right to remove its end from holder 2, spring contact i5 moves from engagement with terminal contact 20 thus opening the primary circuit so that the terminal springs of both lamps are electrically disconnected froxn the circuit. Y

While I have shown my invention as embodied in a construction wherein only the lamp holder 2 is provided with circuit closing means in the transformer primary circuit. I may. if desired, provide such a circuit closing means in both of the lamp holders in which case the lamp holder 3 would be a duplicate of lamp holder 2 except that it would have a greater axial length. 0r, both lamp holders could have an axial length the same as that of the lamp holder I so that a lamp could be first inserted in either. In such case, the transformer primary circuit would be wired through the contacts of both lamp holders. Y

Also, my invention may be used where two lamps are operated in parallel with a ballast designed to operate the two lamps on lead and lag circuits for example, this being a known lamp and ballast arrangement. In such case the primary circuit would be carried through at least one socket of each lamp in series so that the primary circuit would not be closed until both lamps were in place.

The lamp holder is simple in'structure, comprises a minimum number of parts, and is capable of being manufactured at low cost. Also, it can be made relatively shallow in height and of vrelatively small axial length. That it may be so simple in structure and still aircrd a high degree of safety results to a considerable extent from the simple construction of the lamp ends, the lamp holders being especially adapted for use with lamp ends of my improved .construction. Y

In accordance with the provisions of the patent statutes. I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

lWhat I claim as new and desired to secure by Letters Patent of the United States is:

l. In combinationl spaced lamp holders each comprising a tubular housing having an open end, a spring pressed cover disk for the open end having an opening and an axially extending coiled contact spring the inner end of which is connected to said casing and the outer end of which is presented to said cover disk opening. and a tubular lamp positioned between said lamp holders comprising a glass envelope having an integral re-entrant wall at each end forming an end recess and a contact terminal at the bottom of said recess which engages the outer end of said contact spring in the corresponding spaced lamp holder.

2. A lamp holder for a tubular lamp comprising wallsI which define a tubular housing having an open end adapted to receive a lamp end, a. cover disk for the open end of the housing, means forming a stop for the disk, a spring which biases the disk against the stop, said disk being provided with ank opening; a coiled contact spring, one end of which is in line with said disk opening and the other end of which is attached tothe bottom wall of the housing, and a terminal contact in the housing with which a part of the contact spring engages when a lamp is positioned in the lamp holder. y

3. A lamp holder comprising a. tubular housing having an open end, an axially extending coiled spring in the housing having at its inner end an angularly extending arm attached to the housing, the outer end being presented to said Aopen casing end and being adapted to beengaged by a lamp end terminal, and a terminal contact connected to the housing with which said coiled spring engages when the spring is depressed.

4. A tubular lamp lcomprising an elongated glass envelope having an integral reentrant wall at each end forming a recess, a centrally located projection formed integrally with the envelope at the bottom of therecess and a contact member located at the bottom of and protected by said recess, said contact member surrounding the base of the projection with said projection extending beyond the contact member.

GEORGE S. MERRILL. 

